This invention relates in general to electrical connectors and, more specifically, to latchable electrical connectors that are resistant to inadvertent separation and impact or crushing damage.
A wide variety of electrical connectors have been developed to connect electrical cables together and to connect cables to equipment. Several standard connectors have been developed for use with different voltage and current levels. Typically, these have several differently shaped and spaced prongs on one component that slip into correspondingly configured sockets on a second component. While effective in normal household use, these are less than fully effective in many applications and environments.
Where extensive use of extension cables is required, such as in the construction industry or in lighting motion picture or video sets, connectors may be subject to forces tending to pull them apart and to environmental conditions that can contaminate the connector or prongs with water or other materials. Also, these connectors are subject to damage to prongs when disconnected, such as by having prongs bent or damaged by persons stepping on them, being run over by vehicles and the like. When the prongs are contaminated or where the connector is not fully connected, intermittent short circuits between prongs or intermittent open circuits may occur, which are often very difficult to detect and repair. Further, partially inserted prongs may allow the circuit to function, but may allow metallic contamination to touch the prongs causing short circuits or even fires. There is even a possibility of electrocution where a person handling cables comes into contact with prongs that are not fully inserted, particularly on outdoor sites.
Attempts have been made to reduce these problems and dangers by knotting the cables together adjacent to the connection or apply clamping devices to hold the connection together. Knotted cables are cumbersome and provide projections over which people may trip and stumble. The clamps while sometimes effective, are also large and cumbersome and capable of failure if not properly used.
Many connectors are hollow and relatively fragile and subject to damage if subjected to impact or crushing, such as when construction material is dropped on a connector or it is run over by a vehicle.
A number of special connectors have been developed in attempts to overcome these problems. For example, the Armstrong et al. U.S. Pat. No. 3,984,169 discloses a complex keying arrangement in which one component is pivoted about a swivel pin to bring a coded arrangement of blades and slots into mesh to connect a cable to a power distribution panel. A separate latch mechanism is required to keep the unit connected. While useful in this special application, this arrangement has little utility in normal cable to cable or cable to outlet connections.
The Meile U.S. Pat. No. 3,171,704 discloses an electrical connector made up of a first hollow box having a concave surface at one end on which several electrical contacts are formed and a second hollow box having a thin extended finger having a convex surface corresponding to the concave first surface, with three complementary contacts on the convex surface. These two surfaces are pivoted into contact about a pin to make a connection that cannot be separated by a straight line pull. While effective for many purposes, this connector is undesirably fragile for use in difficult environments. For example, the boxes will be subject to breaking, cracking or crushing if stepped upon or run over by vehicles with hard wheels. The thin sleeve that covers the unit, when assembled, may crack and expose the pivoting hooks that are part of conductor system. The thin convex conductor member is liable to bend or break, causing at least intermittent loss of continuity and possible danger when used in a hazardous atmosphere.
In my prior U.S. Pat. No. 5,104,331 and No. 5,408,059 to Goble, I disclosed a damage resistant latching electrical connector for connecting a pair of electrical cables which includes a mechanism to prevent inadvertent disconnection. The present invention is an improvement over these prior patents in the means for locking the male and female components together and in the mounting for the electrical contacts within the housing and to facilitate assembly and repair.
Thus, there is a continuing need for improved electrical connectors for use in circumstances such as where a number of connected cables are connected across floors or roadways, such as in construction, lighting, or in emergency applications, such as natural disaster relief work Connectors are necessary that cannot be separated by straight line pull and will not be damaged or cause electrical hazards when subjected to abuse.
A latching insulated electrical connector apparatus has a first electrically insulating housing having a plurality of abutting electrical insulating members mounted therein and having an electrical contact mounted between each pair of adjacent insulating members. The first housing has a hinge cutout therein. A second electrically insulating housing has an open end and a plurality of protruding electrical contacts mounted therein, each of which aligns with one of the electrical contacts mounted between each pair of insulating members. The second housing has a hinge pin attached thereto across said open end thereof and a pair of locking lugs thereon. The hinge pin is positioned to align with the first housing hinge cutout and one of the locking lugs. The hinge cutout is shaped to fit over the hinge pin and pair of locking lugs in one position and to lock the first and second housings together with the first housing electrical contacts operatively connected to the second housing protruding electrical contacts when rotated to a locking position so that an insulated electrical connector can rapidly connect at least two electrical conductors together.